Silicon insulated test cable by the roll?

Several fleabay sellers offer this, or alternatively consider if it HAS to be silicone cable ? or could ordinary PVC insulated TRI  RATED be used.

Silicone rubber tends to be quite soft and easily damaged by dragging over rough surfaces.  I suspect PVC  would be better

Rapid electronics do 25m reels

Farnell do 30m reels I hope you have deep pockets.

/Unless you really need the heat resistance, I'd suggest extra flexible pvc is a better bet

like this stuff at RS 

For a lot less money you could have a reel of ordinary single, with a short flex tail soldered it for that last 3 feet to the meter or the light fitting..

Could not an r2 lead be normal g/y flex single ?

like this ?

Mike.

Normal single core insulated (standard hookup wire, or tri-rated) might be OK for PE connections or SELV and PELV up to about 60 V DC or 30 V AC, but that's about it in my opinion (however see below). It's really intended for internal wiring, where there's an earthed or insulated enclosure, or a suitable air-gap to a metal enclosure to be classed as double insulation.

Make sure you get make sure you get “reinforced", “double insulated” or “insulated and sheathed” cable for test leads for higher voltages. For hand-held or portable test leads, where leads are more easily snagged or damaged in transit, it's preferable to use insulated and [differently-coloured] over-insulated or sheathed ("double insulated") single-core cables. These are often termed “double insulated test lead wire” or similar. One example (PVC):

Silicon versions are available (e.g. Stäubli SiliVolt-2V range) but these cost more than PVC.

Further, I would always want to use “double insulated” test leads for:

• PE when carrying out insulation resistance tests, prospective earth fault current, loop impedance, and RCD tests on LV circuits, just in case there's a fault on the circuit that's not previously identified.
• SELV and PELV systems with fault currents above 5-10 A, especially those supplied by batteries with high short-circuit currents.

Tri-rated cable is specified to 1000v in BS 6231.  And 600v by UL and CSA

Silicone, silicon is very stiff indeed and unsuitable for cables! Silicones can be very flexible. PVC sheath is a bad idea.

I feel that some of us are over thinking what should be a simple matter.

For brief testing use at a voltage that might be very briefly full mains voltage, but that is normally insignificant, I would use any common type of mains voltage wire. Probably tri rated. Remember that brief tests are not the same as being part of an installation.

dcbwhaley: 
 

Tri-rated cable is specified to 1000v in BS 6231.  And 600v by UL and CSA

But is typically only “single insulated”. Tri-rated is intended for use inside equipment such as switchgear and controlgear. 

broadgage: 
 

I feel that some of us are over thinking what should be a simple matter.

For brief testing use at a voltage that might be very briefly full mains voltage, but that is normally insignificant, I would use any common type of mains voltage wire. Probably tri rated. Remember that brief tests are not the same as being part of an installation.

This all depends on where and why you are carrying out the tests.

At one end of the scale is experiment at home, or perhaps at a stretch on a workshop bench, where, as you say, a quick test using a single insulated cable may be OK.

Towards the other end of the scale is a test on-site where anything might happen, or if you are an employer where these days I'd not like to run the risk of not using the right tools for the job, just in case anything goes awry, given EAWR. Then you consider the larger the turnover of an organisation, the larger the fine … 

We need to remember that this Forum is read by people working across the scale.

I got the impression someone wanted to make a specific test lead arrangement, perhaps to use from time-to-time at work, and given that impression, I wouldn't want to use single-insulated.